I have a Grohe Freehander shower head(1) . The head(2) closest to the pivot has decent volume, the other head only trickles. Even when #l is on off position, #2 will still trickle , even on spray position. Also, I want to note, I cleaned all orifices on both shower heads....help!

SOURCE: water just trickles

Do you have stop valves that are built into the faucet body? Some newer faucets have stops built into the unit on each side of the manifold. Make sure they are open. If you don't, then remove the guts from the manifold body and have someone turn the water on slowly to make sure you don't have something clogged. Also depending on the style have cartridge like guts and can be put in upside down. I'm not sure what you have and I wouldn't know even if you gave me the model number. If this fails, you need to contact the manufacturer. They usually have an 800 number that you can call. Good luck!

SOURCE: water just trickles out

Some of the new units have stops installed on the valve itself. Make sure they are open.

SOURCE: leak where Grohe shower head attached to the threaded pipe

using a pair of vice grips wrapped in a soft towel( to prevent scractching) turn the shower head in a counter clockwise direction to remove it then apply liquid teflon (real-tuf) to the threads on the shower arm and tighten the shower head but dont over tighten it liquid teflon is more effective at sealing leaks than teflon tape and it can be wiped clean